Cigarette filter construction



Feb'. 5, 1957 G. DAVIDSON CIGARETTE FILTER CONSTRUCTION Filed Feb. 5, 1 954 70 CUTTER HNDA5SE/16LER RTION OF MACHINE IN V EN TOR.

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6 a a a9 may a 2,780,573 CIGARETTE FILTER CONSTRUCTION Glenn Davidson, Aurora, Ill. Application February 5, 1954, Serial No. 408,408 4 Claims. Cl. 154-106) In the manufacture of cigarette mouthpiece filters, the customary lines of adhesive to hold the multiplicity of paper sheets together introduce a degree of rigidity which in the case of some papers renders it difiicult to easily assemble in the final rolled form. Where it is attempted to consolidate and unite the paper layers by omitting adhesive and rely upon machine compression, a ditficulty enters that at the bite of rolls through which the assembly must be fed there is a creepage tending to pile up and distort, such as to defeat the formation of an even and satisfactory ribbon. In the present invention this problem is eliminated, and an assembly of sheets to make up a filter ribbon may be formed by travel through a roll compression Zone, and provide a structure having adherence along spaced-apart lines, and

being pliantly amenable to all further assembly operaends, said invention, then, comprises the features hereinafter fully described and particularly pointed out in the claims, the following description and the annexed drawing setting forth in detail certain illustrative embodiments of the invention, these being indicative, however, of but a few of the various ways in which the principle of the invention may be employed.

In said annexed drawing: a

Fig. 1 is a side elevational view of means for production of filter construction in accordance with the invention;

Fig. 2 is a fragmentary elevational view of a slight modification of the middle section of the foregoing;

Fig. 3 is a fragmentary plan view of the same modified construction;

Fig. 4 is an enlarged section on line IV-IV, Fig. I;

Fig. 5 is a similar section showing another slight modification;

Fig. 6 is a fragmentary side elevational view of the middle portion of the mechanism as of Fig. 1 in still another slightly modified form;

Fig. 7 is an enlarged section on the line VII-VII,

to come into the bite of rolls, one of which, 5, Fig. 1,

is smooth faced, and the other, 6, applies pressure at selective small areas to cause compression adherence, and the intervening areas being free from such extreme pressure. If it be attempted to use continuous relief;

l atented Feb. 5, 1957 areas on such roll, the creepage aforementioned leading up to the nip of the roll would be prohibitive, as forming distortions and unevenness defeative of desired functioning. I have solved this difiiculty by providing the relief areas of the roll 6 in discontinuous linear relationship, such that for the assemblage of multiple layers of paper going through the rolls, the compression is in interrupted or dash-like lines. There is compression-adherence of the paper assembly thus at the areas which receive the pressure, and by this arrangement there is no creepage or build-up in front of the nip of the roll. If instead of interrupted lines of compression-adherence, it be desired to have continuous lines of compression-adherence, while this could be attained by a single compression means involving a continuous relief area on a roll, I have found that the continuous-line result can be attained by the form of the invention shown in Figs. 2 and 3, with a tandem arrangement of compression-adherence areas. Here, the periphery provides narrow areas 8' interrupted, somewhat resembling a circular saw if the points of the teeth were ground ofi to leave spaced truncated projections as the periphery. And the gearing together of the successive rolls is so synchronized that the second roll applies the pressure of its series of peripheral compression projections to compress the portions which are skipped by the first roll. Hereby, the end result is a continuous line 16 of compression-adherence in the superposed tissue. Whether the structure of the roll in Fig. l is of discs with interrupted or spaced projections 8' as in Fig. 3, the single roll then forming a lineof interrupted compression-adherence 16', Fig. 8; or the tandem arrangement of rolls for efiecting'compression-adherence of the superposed sheets S as shown in Figs. 2 and 3 be used, in any case the creepage and distortion ditficulty is obviated.

The means for feeding the plurality of superposed thin sheets of paper S may involve drive and driven pulleys 2, 3, Fig. l which carry belts 4 to come into contact with the paper sheets S and forward the same together through the rolls 5 and 6. Foregoing, I have shown how the creepage problem can be eliminated by applying adherence-compression to the paper sheets by means of roll surfacing having interrupted or discontinuous compression areas. I have found that the distortion problem in the paper also can be eliminated by providing positive gripper means to force the assembly of paper into the nip of the rolls, and if this be done, roll 6 can successfully operate even though its relief compression areas were to be continuous. Rolls such as roll 6 may be of integral construction, but it is generally preferable to have an assemblage of discs 7, 8, 9 suitably bolted together to operate as an integral roll. The number of these discs may be as desired and according to the widthv of ribbon-like product desired from the machine. As shown in the Fig. 4 form, the disc 7 is provided with a. cutting edge 10, and its action is to both compress the superposed thin sheets at its point of contact against the lower smooth roll, and also sever the paper. As gripper means for positive feed of the paper into the biteof the rolls, the belts 4 not only serve as general "ice guide-means, but here are in' the form of rubber V-beltspresent invention. It is understood that the contour of the roll 6, by reason of its assemblage of discs 7, 8, 9

provides sufiicient space between the compression discs: for the gripper V-belt. The paper assemblage S is forwees thus. b the er n sr b lt l ae the smooth support table 12, and if desired, pressure shoes 13 may be mounted to bear against the V-belts through the bite of the roll pair 5, 6, the roll discs between the compression discs, as aforementioned being sufliciently recessed to accommodate the belts and the pressure shoes. The mounting of the pressure shoes 13 involves backing springs, as need not be further detailed here, being of a type known generally. Thus, starting as aforcenoted with a plurality of sheets of thin paper S, these are brought into the roller zone where they are shaped together in the space defined by the sides of successive forms a ribbon, product, which, as shown in the fragmentary plan view of Fig. 9, has adhesion lines 16 of compression, the discs 7 accomplishing the adherence and at the same time slitting edges 17.

While a gripper belt or draw belt in the form of a V-belt, as described in connection with Fig. 4 is generally satisfactory, in some cases another form of belt such as wires 4", Fig. 5 are convenient, these being of sutficient section to function about the drive and driven pulley and provide compression against the paper assembly. Here the discs 8" in the upper roll 6", which are of smooth periphery, bear against the wire belts 4, and result in a continuous line of compression adherence in the ribbon as it emerges from the molding zone. The product is as illustrated in Fig. 9, plan view.

Instead of continuous traveling gripper means on the belt order as foregoing, in some cases and with some materials it sufiices to draw the feed paper superposed sheets through the bite of the roll pair 25, 26, Fig. 6, and a reciprocating gripper 27, pivoted at 28, is reciprocated back and forth by suitable means, for example a crank and connecting link 29, the gripper 27 thereby urging the paper assemblage at the bite of the roll; and as shown at Fig. 7 in enlarged cross-section the paper assemblage again is formed as a continuous ribbon with portions, 20 of tin-adhered layers, and lines 21 of compressed adherence, the compression discs 8 here being the same as in Fig. 4, and again there may be slitting or trimming discs 7 to cut in Widths as desired, but preferably of a width just equalto the circumference of the finished cigarette.

The compression means for forming the compressionadherence areas in the assembled paper may thus be used alone as. the means for obviating distortion at the nip of. the rolls, in such case the belts 4 being merely guiding means; or positive gripper means may be employed, as

noted, toobviate distortion at the nip of-thev rolls, such grippernieans being of. rubber V-belt character as described, orof. reciprocating mechanical gripper character; or again lzmay employ both the interrupted surface com: pression roll and the positive gripper means together. In any case, a filter ribbon product is obtained, free from manufacturing difiiculty, and which is uniformly even in its construction, having linear areas of compressionadherence, interrupted, or continuous if the tandem compression-adherence rolls be employed, and between the lines of compression-adherence the paper assemblage is compact, but not compressed, and thereby admirably adapted to accomplish its filter function.

For. attaining a higher standard of filtering efficiency (f. c,), I have discovered that asurprising increase in thefiltering efficiency results if crepe paper is employed and is lied in orientation with the ridges and depressions of "the, crepin transyerse. to .the longitudinal din'iensipn V of the paper. In this manner a particularly important need stil s. inven ion s he ob ain ng a namum filtering effect per gram of paper used. And, the weight in grams of the tobacco tars absorbed by one gram of paper is here termed the filtering coefficient (f. 0.). Thus, as seen in plan view, Fig. 8, the ridges and depressions of crepe paper 30 are transverse of the longitudinal axis of the ribbon creped waves, in other words, extend across the ribbon at right angles to its length; and, whereas it is found that if the crepe ridges and depressions or creped waves extend lengthwise of the mouthpiece filter plug ribbon, the f. c. is substantially the same as for flat sheets of the same thickness; the filter action is very greatly improved where the creped waves extend across the ribbon.

Embossing, in various designs, applied to thin sheets also very essentially raises the f. c., in much the same manner as creped waves extending across the ribbon.

As seen, the thin sheets or strands are adhered to each other by areas of compression along lines parallel with the length of the ribbon and spaced somewhat in from the edges of the ribbon. For example, a desirable arrangement is two such lines spaced to divide the width of the ribbon approximately into thirds. Although a single such line near the center of the ribbon also works well.

A continuous line of compression adherence is mostly desirable but in no sense a necessity. Such a continuous line of compression adherence produces a valley elfect in the assembly simulating the fly-cutter kerfs shown in Fig. 22, of my Patent No. 2,208,839. Such valleys are of substantial assistance in smoothly folding the ribbon, (or sections thereof) around an axis parallel to its, length.

Either, a continuous line or a discontinuous line of compression adherence at or near each edge of the ribbon is highly desirable to prevent damage to the ribbon (or section thereof) while being assembled into the final cigarette. These lines of adherence are in addition to those mentioned above, which are primarily helpful in giving smooth folding around the axis parallel to the length. of the ribbon.

In fact, we find that certaintypes of thin sheets even though creped or embossed are sufficiently soft to fold reasonably well around an axis parallel with the length of the ribbon when adhered only by lines of compressionadherence at or near the longitudinal edges. On the other hand, if such soft sheets were adhered by corresponding lines of adhesive, the adhesive, when enough is applied to produce the necessary adherence, migrates so far along the sheets toward the center of the ribbon as to render the entire assembly too rigid as to be satisfactorily folded.

As a further feature, sheets of thin paper for molding into mouthpiece filter plug ribbons may be of stock which is loaded with filter aid material, such as fullersearth, silica gel, aluminum oxide, etc.

Further, thin sheets of materials such as cotton laminae, formed by dry methods on a textile carder, also=asbestos paper, and very thin fabrics, may be interleaved between the thin sheets of suitably soft paper, and this assembly also bonds together satisfactorily along lines of compression-adherence. Such materialsmay be concisely called paper like in that-they are in the form of thin; sheets and amenable to compression-adherence provided they are with the sheets of paper.

The mouthpiece filter ribbon, passing to the cutter and assembler portion of the cigarette machine may be cut and attached to a heavier sheet of paper if desired and this maybedone either before or after or simultaneously with the formation of the lines of compression-adherence- A. multiplewidth, and appropriate subsequent or simultaneously,slittinginto. ,unitl ribbons is particularly desirable in,.practice, although a single width ribbonmay, be formed if preferred.

This application is a continuation in part and as to common subject matter, of my patent application Serial No. 744,925, filed April 30, 1947, now Patent No. 2,668,- 544, dated February 9, 1954. Where my improved ribbon," such as shown in Figs. 8 and 9, is provided with two intermediate lines of compression-adherence, the resulting filter element, when such ribbon is rolled into a cylinder or rod and the latter thereupon cut into suitable lengths and inserted in the cigarette, will resemble that shown in Fig. 10 of said patent. On the other hand, where lines of compression-adherence are provided along the lateral edges only of the ribbon, the resulting filter element will resemble that shown in Fig. 11 of said patent.

Other modes of applying the principle of the invention may be employed, change being made as regards the details described, provided the features stated in any of the following claims or the equivalent of such be employed.

I therefore particularly point out and distinctly claim as my invention:

1. In the manufacture of cigarette mouth-piece material, the steps of superimposing in registry a plurality of creped paper strips having transversely extending crepe waves, to form a ribbon, gripping such ribbon laterally and movably to advance the same lengthwise, and feeding the ribbon in this manner into the nip of opposed rolls formed cooperably to produce lines of compression adherence of the strips which are parallel with the length of the ribbon, the gripping action compacting the ribbon by a line of compression-adherence which is parallel to the length of the ribbon, the ribbon being of indefinite length and of width approximately equal to the circumference of a cigarette.

4. The article set forth in claim 3 characterized further in that said strips are adhered by two lines of compression-adherence respectively at the longitudinal edges of the ribbon.

References Cited in the file of this patent UNITED STATES PATENTS 1,941,255 Fourness Dec. 26, 1933 2,202,839 Davidson June 4, 1940 2,321,985 Briggs June 15, 1943 2,668,544 Davidson .L Feb. 9, 1954 FOREIGN PATENTS 236,957 Great Britain Oct. 7, 1926 

1. IN THE MANUFACTURE OF CIGARETTE MOUTH-PIECE MATERIAL, THE STEPS OF SUPERIMPOSING IN REGISTRY A PLURALITY OF CREPED PAPER STRIPS HAVING TRANSVERSELY EXTENDING CREPE WAVES, TO FORM A RIBBON, GRIPPING SUCH RIBBON LATERALLY AND MOVABLY TO ADVANCE THE SAME LENGTHWISE, AND FEEDING THE RIBBON IN THIS MANNER INTO THE NIP OF OPPOSED ROLLS FORMED COOPERABLY TO PRODUCE LINES OF COMPRESSIONADHERENCE OF THE STRIPS WHICH ARE PARALLEL WITH THE LENGTH OF THE RIBBON, THE GRIPPING ACTION COMPACTING THE RIBBON LATERALLY SUFFICIENTLY TO FORCE THE SAME BETWEEN THE COMPRESSION ROLLS WITHOUT RELATIVE DISPLACEMENT OF THE COMPOSITE STRIPS.
 3. AS AN ARTICLE OF MANUFACTURE FOR USE IN THE MAKING OF CIGARETTE FILTER PLUGS, A RIBBON COMPRISING A PLURALITY OF STRIPS OF CREPED PAPER HAVING TRANSVERSELY EXTENDING CREPE WAVE, SAID STRIPS BEING ADHERED TOGETHER BY A LINE OF COMPRESSION-ADHERENCE WHICH IS PARALLEL TO THE LENGTH OF THE RIBBON, THE RIBBON BEING OF INDEFINITE LENGTH AND OF WIDTH APPROXIMATELY EQUAL TO THE CIRCUMFERENCE OF A CIGARETTE. 